Brass rubbing off in chamber

[Tac-O]

I have a pretty new barrel and the chambering job was pretty rough, done with a much too old reamer. The smith also honed the the finish in the chamber to have a bit more grip.

I them took it to another guy to have him smooth out some of the marks in the chamber. He said it was pretty rough.

Anyway, after shooting 20 rounds I can see that some brass is getting rubbed off and left in my chamber near the base. It's not extreme, I don't think. I don't know how much is too much. I don't have any extraction issues.

For extra info: when I get near max pressure, I will still get flatter primers, ejector marks, and the slightly more case diameter expansion near the base/web.

Doni need to worry about this? Is it going to reduce my case life or eventually run enough off to weaken the case web area and make a head separation more likely?

Here is the brass in the chamber. It's not quite this bad, but nearly the same I think. This picture is from before I had the second guy smooth it out some.

 

[tobnpr]

Removing deep gouges from the chamber walls is more than "honing". If the gouging is deep enough to strip and hold brass- that's pretty deep. A chamber hone is for removing light scratches. I can't tell from the pictures- is the gouging circular as opposed to linear (down the length of the chamber)? Usually circular gouging is caused if the smith begins to withdraw the reamer before the spindle has come to a complete stop. A chip gets caught between a reamer flute and the chamber wall and as it's withdrawn creates a "screw" like scratch in the chamber. I have no explanation for them if they're running the length of the chamber- usually machining artifacts in barrels are circular by nature of the work.

Anyway...
You didn't mention how the rifle shoots. If it's shooting well, you're not having extraction issues, and if the damage to the brass isn't extreme you don't need to do anything. The correct "fix" for scratches that deep is to set the barrel back a revolution or two (whatever I need to clean up) and deepen the chamber. This should be done at no charge by the smith that did the work originally- but given that he decided to try to hone them out- and then you had to take it to another smith anyway, probably not a good option.

 

[Tac-O]

Thanks for your insight. The marks are circumferential in the chamber. I'll get some fresh pictures pre and post cleaning it out possibly this evening and post them.

It will shoot well and I'm not concerned about the brass looking nice. I'm just concerned about shorter case life or a possible case head separation after X many firings.

 

[Carlos88]

I'd have the barrel set back one turn (if possible) and drilled again. Preferably from a good 'smith. I'd ask the first guy for your money back. Not even close to right.

 

[FEENIX]

Is this your 30-.284? If so, I am sorry you are having all sort of challenges with it.

 

[Tac-O]

Yup. It shoots ok though so I'll knock em off one at a time and eventually have it setback.

 

[Tac-O]

Here's a few pictures of the chamber before and after cleaning tonight. I don't think the chamber through the body looks particularly rough except for one scratch that's parallel to the chamber. The neck portion and throat is real rough. Included the neck just because. It leaves a series of annular marks or ribs on my case necks after firing. It doesn't leave any brass in the chamber neck.

Loads and extracts easily.

 

[Tac-O]

And a picture of brass, twice fired

 

[VaqueroApache]

My 7mm08 brass used to look like that. I used light spinning strokes on an undersized wooden dowel with a small strip of fine emery cloth to smooth it out then some 000 steel wool. Never had that issue any.ore and Im on my 5th loading of the same brass no separations or cracks noted when inspected after each firing. Still shoots 1/4 to 1/2" groups. Giving it to my son.

 

[Tac-O]

My 7mm08 brass used to look like that. I used light spinning strokes on an undersized wooden dowel with a small strip of fine emery cloth to smooth it out then some 000 steel wool. Never had that issue any.ore and Im on my 5th loading of the same brass no separations or cracks noted when inspected after each firing. Still shoots 1/4 to 1/2" groups. Giving it to my son.

Awesome!! I think I'm too nervous to try that myself.

I'm wondering if it could be some type of brass vs chamber size and brass hardness issue. I don't think the chamber body finish looks that rough through my scope... At least to my untrained eye

 

[26Reload]

The brass is showing a little wear...but if it's shooting good and no separations or heavy bolt.....id do the 000 wool or lite scotch pad and clean it really good....oil it good...spin a fiber brush on a drill in there for a couple minutes....might be all it takes to clean it up nice and purdy......

 

[Treeslug]

Awesome!! I think I'm too nervous to try that myself.

I'm wondering if it could be some type of brass vs chamber size and brass hardness issue. I don't think the chamber body finish looks that rough through my scope... At least to my untrained eye

It doesn't look that rough through your scope? It looks like a worn-out automobile disc brake that was running a well-worn set of cheap brake pads. From the pictures, it appears that you are married. There is your answer. Go ask your wife, or your best friend's wife, for her opinion. Women know everything about anything. But seriously, your first gun smith, if you can call him a smith after turning out work like that, is the real problem, and I would be scared to let him try to fix the problem. You got screwed, dude.

 

[Tac-O]

It doesn't look that rough through your scope? It looks like a worn-out automobile disc brake that was running a well-worn set of cheap brake pads. From the pictures, it appears that you are married. There is your answer. Go ask your wife, or your best friend's wife, for her opinion. Women know everything about anything. But seriously, your first gun smith, if you can call him a smith after turning out work like that, is the real problem, and I would be scared to let him try to fix the problem. You got screwed, dude.

Yup... I'm not working with that guy again.

 

[jimwest]

Just a question for somebody that has experience with this issue. Trying to put it in the simplest of words: When shooting a round you are fireforming the brass to match the imperfections of the chamber. And when ejecting the fired brass, a portion of the case is 'abraded' off and leaving the residue on the chamber. Is this what is happening?